Gettering of metal impurities by cavities in silicon

Conference · Fri Dec 31 04:00:00 EST 1993

OSTI ID:10115811

Myers, S M; Follstaedt, D M; Bishop, D M; Medernach, J W

Ion implantation of He into Si followed by annealing {approx_gt}700C produces nanometer-scale cavities from which the He has diffused. Experiments utilizing Rutherford backscattering spectrometry and transmission electron microscopy show that these cavities trap Cu impurities with a binding energy of 2.2{plus_minus}0.2 eV relative to solution, whereas the binding energy in precipitates of the equilibrium silicide phase Cu{sub 3}Si is determined to be 1.7 eV. Preliminary results indicate that Ni impurities also are bound more strongly at internal surfaces than in silicide precipitates. These findings suggest that cavity traps may provide exceptionally effective gettering of transition-metal impurities. Additional properties relevant to gettering are discussed, including fundamental differences between trapping and precipitation dynamics, the replacement of Cu by H atoms at internal surface sites cavity-associated electronic levels in the band gap, and microstructural stability of the cavities.

• Research Organization: Sandia National Labs., Albuquerque, NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 10115811
• Report Number(s): SAND--93-2047C; CONF-940537--1; ON: DE94005248; BR: GB0103012
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101
CAVITIES
COPPER
GETTERING
IMPURITIES
ION IMPLANTATION
NICKEL
PREPARATION AND FABRICATION
SILICON
TRAPPING